1. Field of the Invention
The present invention relates generally to the field of telephone switching equipment. More specifically, the present invention relates to verifying subscriber information stored in various components of a cellular telephone system to ensure that subscribers are correctly billed for the services they use.
2. Background of the Invention
A critical issue facing cellular telephone companies is ensuring appropriate subscriber billing. For example, it is important to ensure that subscribers are billed for services they use, and not billed for services they do not use. Billing errors result in upset customers, and costly allocation of cellular telephone company resources to locate and fix problems leading to billing errors.
Data regarding particular subscribers and the services that they subscribe to are usually located in several places in a telephone system. A home location register (HLR) stores subscriber data that can be used by a switch in a cellular telephone network to determine the services that a subscriber subscribes to. The HLR is generally located on a service control point (SCP) of the subscriber's provider of record. The HLR contains data that is used to identify and verify subscribers, as well as data indicating what services subscribers can use and data used to provide these services.
The data in the HLR is also used when a subscriber is roaming. A subscriber is roaming when he or she is outside the coverage area of the service provider of record. When roaming, the visited telephone system obtains a copy of the subscriber's data record from the roaming subscriber's HLR and stores it as a temporary record in a visitor location register (VLR). The VLR is maintained during the duration of the subscriber's roaming. It is used by the visited telephone company to provide services in accordance with the services identified by the temporary record stored in the VLR, as well as to provide billing identification information so the visited system can appropriately bill the roaming subscriber.
Cellular telephone networks also contain a billing system that calculates and distributes bills to subscribers for the services they use. Like the HLR, the billing system comprises information regarding each subscriber in the system. The billing data for each subscriber provides information on the services accessible by the subscriber.
The subscriber data located in both the HLR and billing systems includes data regarding the services to which each subscriber has subscribed. The services can be individual services or bundled in service plans. A service plan generally offers a combination of services and service features at a reduced billing rate. Services include local telephone service, long distance telephone service, cellular telephone service, paging service, Internet service and other services. Services for purposes of the present disclosure also include features such as caller ID, call waiting, three-way calling, call return, special ring and other features.
Services are provided to subscribers based on the subscriber data stored in the HLR. Thus, if subscriber data in the HLR indicates a particular subscriber has caller ID, that subscriber is provided caller ID whether the subscriber is billed for it or not. Also, billing is generated based on the subscriber data stored in the billing system. Thus, if the subscriber data in the billing system indicates a particular subscriber has caller ID, that subscriber is billed for caller ID, whether or not the subscriber is actually authorized to use caller ID by the subscriber database.
As a result, it is apparent that significant problems can arise if the subscriber data stored in the HLR and/or the billing system is inconsistent. Such inconsistency can arise if, for example, there are duplicate subscriber records for a particular subscriber that indicate the subscriber subscribes to different and inconsistent services.
In addition, billing problems can occur if the data stored in the HLR differs from the subscriber data stored in the billing system for a particular subscriber. For example, if subscriber data in the HLR indicates that a subscriber can use a particular service, but the subscriber data in the billing system indicates the subscriber does not have access to that service, the subscriber will be able to use the service but will not be billed for that use. Such use represents a lost revenue opportunity for the service provider. In addition, this use by the non-paying subscriber represents a drain on resources that could be used by other subscribers.
Similarly, if subscriber data in the HLR for a particular subscriber indicates that the subscriber does not have access to a particular service, but the billing system subscriber data indicates that the subscriber does have access to the service, the subscriber will be charged for the service even though the subscriber cannot actually use the service. This situation leads to complaints from subscribers who are billed for services they do not use. In addition, expensive telephone company resources are required to track, locate and solve the problem.
A significant problem existing in current cellular telephone systems is that there is no convenient way to compare HLR subscriber data with billing data for consistency. As a result, problems often go undetected unless a customer complains to the telephone company due to the improper billing (which many not happen, for example if the customer is being under-billed).